Low distortion filters for separating frequency or phase modulated signals from composite signals Patent #: 4747140
ApplicationNo. 10083052 filed on 02/26/2002
US Classes:381/2, Broadcast or multiplex stereo381/3, FM final modulation327/309, By limiting, clipping, or clamping455/260Phase lock loop or frequency synthesizer
ExaminersPrimary: Pendleton, Brian T.
Attorney, Agent or Firm
International ClassH04H 5/00
AbstractA system and method are disclosed for performing digital multi-channel decoding of a BTSC composite audio signal. Analog-to-digital conversion is performed on a composite analog audio signal at a fast clock rate to generate a composite digital audio signal at a first sample rate. Digital frequency compensation is performed on the composite digital audio signal at the first sample rate to generate a compensated composite audio signal. Digital channel demodulation and filtering are performed on the compensated composite audio signal at the first sample rate to generate a first single channel audio signal at a second sample rate.